There are a number of electronic smart safe products on the market that can both electronically recognize currency deposited and securely store the deposited currency. An example of this technology is described in U.S. Pat. No. 7,516,832 which is assigned to the assignee of the current invention and is incorporated herein by reference in its entirety. This technology has the limitation of being a stationary container normally bolted in place. Additionally, this technology is designed to be heavy using thick gauge steel and reinforced for security. Frequently, to increase security when removing the collected currency from the electronic support safe, an armored car service is used.
When the added cost of using an armored car service is prohibitive, alternatives are available. Devices used to securely transport paper currency are offered in many forms and styles from sturdy metal cases to locked nylon zipper bags and simple bank deposit bags. In recent years, a number of more sophisticated cash carrying devices have been introduced that add indelible ink deployment mechanisms to devalue currency in the event of theft.
These transport systems typically require that the user first store currency in an intermediate location that is often less protected from theft such as the cash drawer of a point-of-sale (POS) system. While in the intermediate storage location, the cash is vulnerable to theft by an external threat, such as a robber or an internal threat, such as an employee.
Many existing systems use mechanical keys or a range of electronic key options, including radio frequency identification (RFID) tags, Dallas keys, or an optical communication link, to disarm the cash carrying devices to allow retrieval of the cash. These types of systems are vulnerable to key-theft. It is well known that biometric authentication methods can be much more effective in preventing unauthorized access, but such approaches tend to add significant cost as in the case of fingerprint scanners, palm print scanners, retinal scanners, or voice print analyzers. In U.S. Pat. No. 4,805,222, Young discloses an alternate method of biometric authentication through the analysis of an individual's typing patterns including the timing between characters and the pressure of each keystroke. By applying probability techniques, the natural typing cadence of particular users are compared against a database of pre-captured typing cadences to scan for a match. This technique involves the use of a large database containing typing pattern information for a variety of users and employs rigorous computer processing and analysis to validate the keystroke dynamics. The use of keyboard pressure sensing requires the use of specially design keypad interfaces with built-in pressure sensors.
Kellas-Dicks in U.S. Pat. No. 8,332,932 offers an alternative algorithm for analyzing keystroke dynamics based on not only dwell time between characters, but also through the analysis of derivatives and other mathematical products determined based on collected key press timing information. In both the approaches taken by Young and Kellas-Dicks, the objective is to provide authentication of a user based on their natural typing patterns. As a result, the data processing burden is substantial.
In the Eye in the Sky security system project described in, Eye in the Sky Security System Project—May 2004, Aaron Dobbins and Fran Ianacci, http://people.ece.cornell.edu/land/courses/ece4760/FinalProjects/s2004/fci2/highleveldesign.html (“the Dobbins method”), a simpler keystroke dynamics authentication scheme is disclosed in which a user is prompted to come up with a unique keystroke pattern for their pass code. The user is given a blinking light emitting diode (LED) prompt to aid in both creating and recalling their unique timing sequence. In this manner, a deliberate keypad sequence can be much more easily authenticated with keystroke timing and character information alone.